fix: avoid duplicate backlog hydration load

__tests__/stores/product-workspace/store.test.ts

@@ -257,6 +257,35 @@ describe('selection cascade', () => {
     expect(s.relations.taskIdsByStory).toEqual({})
     expect(s.loading.loadedProductId).toBeNull()
   })
+
+  it('setActiveProduct kan alleen context zetten zonder full backlog load', () => {
+    useProductWorkspaceStore.getState().hydrateSnapshot(
+      snapshotWith(
+        [makePbi({ id: 'p-1' })],
+        { 'p-1': [makeStory({ id: 's-1', pbi_id: 'p-1' })] },
+        { 's-1': [makeTask({ id: 't-1', story_id: 's-1' })] },
+        { id: 'prod-1', name: 'Product 1' },
+      ),
+    )
+    useProductWorkspaceStore.setState((s) => {
+      s.context.activePbiId = 'p-1'
+      s.context.activeStoryId = 's-1'
+    })
+    const fetchSpy = vi.spyOn(globalThis, 'fetch')
+
+    useProductWorkspaceStore
+      .getState()
+      .setActiveProduct(
+        { id: 'prod-1', name: 'Product 1' },
+        { load: false, preserveSelection: true },
+      )
+
+    const s = useProductWorkspaceStore.getState()
+    expect(fetchSpy).not.toHaveBeenCalled()
+    expect(s.context.activePbiId).toBe('p-1')
+    expect(s.context.activeStoryId).toBe('s-1')
+    expect(s.entities.pbisById['p-1']).toBeDefined()
+  })
 })
 
 // ─────────────────────────────────────────────────────────────────────────

app/(app)/products/[id]/page.tsx

@@ -151,6 +151,7 @@ export default async function ProductBacklogPage({ params, searchParams }: Props
       <div className="flex-1 overflow-hidden">
         <BacklogHydrationWrapper
           productId={id}
+          productName={product.name}
           initialData={{
             pbis: pbis.map((p) => ({ id: p.id, code: p.code, title: p.title, priority: p.priority, sort_order: p.sort_order, description: p.description, created_at: p.created_at, status: pbiStatusToApi(p.status) })),
             storiesByPbi,

app/(mobile)/m/products/[id]/page.tsx

@@ -91,6 +91,7 @@ export default async function MobileProductBacklogPage({ params, searchParams }:
     <div className="flex flex-col h-full">
       <BacklogHydrationWrapper
         productId={id}
+        productName={product.name}
         initialData={{
           pbis: pbis.map((p) => ({ id: p.id, code: p.code, title: p.title, priority: p.priority, sort_order: p.sort_order, description: p.description, created_at: p.created_at, status: pbiStatusToApi(p.status) })),
           storiesByPbi,

components/shared/set-current-product.tsx

@@ -8,9 +8,11 @@ import { debugProps } from '@/lib/debug'
 // De voorganger (stores/product-store.ts) wordt in Story 8 (T-876) verwijderd.
 export function SetCurrentProduct({ id, name }: { id: string; name: string }) {
   useEffect(() => {
-    useProductWorkspaceStore.getState().setActiveProduct({ id, name })
+    useProductWorkspaceStore
+      .getState()
+      .setActiveProduct({ id, name }, { load: false, preserveSelection: true })
     return () => {
-      useProductWorkspaceStore.getState().setActiveProduct(null)
+      useProductWorkspaceStore.getState().setActiveProduct(null, { load: false })
     }
   }, [id, name])
 

stores/product-workspace/store.ts

@@ -78,7 +78,10 @@ interface State {
 interface Actions {
   hydrateSnapshot(snapshot: ProductBacklogSnapshot): void
 
-  setActiveProduct(product: ActiveProduct | null): void
+  setActiveProduct(
+    product: ActiveProduct | null,
+    options?: { load?: boolean; preserveSelection?: boolean },
+  ): void
   setActivePbi(pbiId: string | null): void
   setActiveStory(storyId: string | null): void
   setActiveTask(taskId: string | null): void
@@ -223,15 +226,18 @@ export const useProductWorkspaceStore = create<ProductWorkspaceStore>()(
       })
     },
 
-    setActiveProduct(product) {
+    setActiveProduct(product, options) {
       const requestId = newRequestId()
       const productChanged = get().context.activeProduct?.id !== product?.id
+      const shouldResetSelection = productChanged || !options?.preserveSelection
 
       set((s) => {
         s.context.activeProduct = product
-        s.context.activePbiId = null
-        s.context.activeStoryId = null
-        s.context.activeTaskId = null
+        if (shouldResetSelection) {
+          s.context.activePbiId = null
+          s.context.activeStoryId = null
+          s.context.activeTaskId = null
+        }
         s.loading.activeRequestId = requestId
 
         if (productChanged) {
@@ -252,7 +258,7 @@ export const useProductWorkspaceStore = create<ProductWorkspaceStore>()(
       // selectie kan herstellen. T-857: restore-flow start na ensureProductLoaded.
       writeProductHint(product?.id ?? null)
 
-      if (product) {
+      if (product && options?.load !== false) {
         const productId = product.id
         void (async () => {
           await get().ensureProductLoaded(productId, requestId)